Contemporary aircraft engines include electric machine assemblies, or generator systems, which utilize a running aircraft engine in a generator mode to provide electrical energy to power systems and components on the aircraft. Some aircraft engines can further include starter/generator (S/G) systems or motor/generator (M/G), which act as a motor to start an aircraft engine from its high pressure spool or a motor to drive the engine from its low pressure spool, and as a generator to provide electrical energy to power systems on the aircraft after the engine is running. Motors and generators can be wet cavity systems, wherein a cavity housing the rotor and stator is exposed to liquid coolant, or dry cavity systems, wherein the cavity is not exposed to liquid coolant. Dry cavity cooling can also utilize liquid coolant in one or more contained cooling systems, but they are still considered dry cavity so long as the cavity is not exposed to liquid coolant.